BRL-CAD is a powerful cross-platform Open Source combinatorial Constructive Solid Geometry (CSG) solid modeling system that includes interactive 3D solid geometry editing, high-performance ray-tracing support for rendering and geometric analysis, network-distributed framebuffer support, image and signal-processing tools, path-tracing and photon mapping support for realistic image synthesis, a system performance analysis benchmark suite, an embedded scripting interface, and libraries for robust high-performance geometric representation and analysis.

Scribus is an application for professional visual layout of printed documents (newspapers, magazines, brochures, literature, etc.) capable of creating high-quality pages for any purpose - be it replication for printing or electronic distribution.
Scribus supports all the features of professional publishing systems, such as extensive capabilities for layout and pre-press preparation of text, the CMYK color model, Spot Colors, the ICC color output management system, and the creation of PDF files.
This is similar to AdobeInDesign or QuarkXPress.